Synchronizing mechanism for reversible-pitch propellers



E. G. McCAULEY.

SYNCHRQNIZING MECHANISM FOR REVERSIBLE PITCH PROPELLERS.

APPUCATION FILED OCT, H, 1921.

1 7 830 Patnted Sept. 5, 1922.

4 SHEETS-SHEET l.

-E. vG" xMcCAULEY. SYNCHRONIZING MECHANISM FOR REVERSIBLE :PIT'CH PROWELLERS. APPLI CATIO'N FILED OCTJIL. 1921.

1 ,427,830, Patented Sept. 5, 1922.

4 SHEETSSHEET 2.

E. GfMcCAULEY. SYNC'HRONlZlNG MECHAN1SM. FOR 'REVERSIBLEPITCH PROPELLERS.

APPHCA EON HLED OCT, I], 1921.

Pzitented Sept. 5, 1922.

4 SHEETS-SH EH 3.

E. e. McCAULEY. SYNCHRONIZING MECHANISM FOR REVERSIBLE PITCH PROPELLERS. APPLICATION FIlED OCT. H, 192].

Patented Sept. 5, 1922.

PATENT OFFICE.

. ERNEST G. MCGAULEY, OF DAYTON, OHIO.

SYNCHRONIZING MECHANISM FOR REVERSIBLE-PITCH PROPELLERS,

Application filed October 11, 1921. Serial No. 506,960.

- To all whom it may concern:

Be it known that I, ERNEST Gr. MGCAULEY, a citizen of the United States, residing at Dayton, in the county of Montgomery and State of Ohio, have invented certain new and useful Improvements in Synchronizing Mechanism for Reversible-Pitch Propellers, of which the following is a specification.

This invention relates to a synchronizing mechanism for reversible pitch propellers whereby the throttle valve of the engine of the aircraft is automatically controlled si-' multaneously with the angular movements of the propeller blades.

The main purpose of the invention is to provide mechanism of the above mentioned type so that the engine speed or revolutions of the propeller cannot exceed a safe limit while the angularity of the blades is being changed from one position to another.

My invention also aims to provide mechanism having compensating devices so arranged that the throttle valve may be manually actuated to off position at any time.

Furthermore, according to my invention,

a dual or multiple control is established whereby the reversing mechanism for the propeller and the throttle valve of the engine may be operated in synchronous relation from either the front or rear cockpits of the aircraft.

The invention is described in connection with the accompanying drawings and the preferred construction, as well as various novel features andfunctions of the mechanism will become apparent on reference to.

the subjoined specification. In the drawlngs:

Fig. 1 is a side elevation of an airplane showing somewhat diagrammatically, my

mechanism applied thereto.

Figure 2 is a part sectional view and part plan view of the main control'bracket. v

Fig. 3 is a rear elevation of the control bracket.

Fig. 4 is a transverse vertical section through the control bracket.

Fig. 5 is an end view of the main control bracket.

Fig. 6 is .a front view of the cam disk and throttle and compensating levers associated V therewith.

Fig. 7 is a part sectional view and part plan VIEW Off the auxiliary control bracket.

Fig. 8 is a diagrammatic plan view of the connections between the main and auxiliary control means and the propeller reversing mechanism.

The numeral 10 designates the reversible propeller with which is associated a reversing mechanism 11 of any suitable type. This reversing mechanism is adapted to be actuated by a shaft 12 which is connected to the main control means 13 as will hereinafter appear. The internal combustion engine 14 of the aircraft is provided with the carbureters 15 having the throttle valves 16, which are colmected by means of suitable links and levers 17 to an appropriate control lever mounted upon the control means 13. The engine 14 is also provided with i nition devices 18 which are adapted to be a justed by means of suitable links and levers 19 leading to the control means 13. A device 8 for adjusting the explosive mixture is connected to a suitable lever of the control means 13 by the rods 9. An auxiliary control means 20 is provided in the rear cockpit of the machine and this auxiliary control means is connected to the main control means 13 by transmitting devices hereinafter described.

The main control means is mounted in bracket 21, which is provided with a plurality of bosses 22 suitably bored and threaded as at 23 for receiving fastening devices (not shown) whereby the bracket may be supported in the fuselage at some convenient point. The bracket 21 is provided with spaced end bosses 24, 25, and with a central boss 26. A stub shaft 27 is rotatably mounted in the hollow boss 25 and a similar stub shaft 28 is mounted in the hollow boss 24 by meansof suitable radial bearings 29. ating shaft 30 is rotatably mounted in the central boss 26 by means of ball bearings 31. The spaced bosses 24 and 25 are connected by means of a rear plate 32 in which a. roller bearing 33 is mounted for receiving the rear endof the operating shaft 30. The forward end of the operating shaft pro'ects beyond the boss 26 andhas mounted t ereon operating hand wheel 34 which is secured on a polygonal section of the operating shaft by the roller into contact with the cam disc.

means of a nut engaging the screw threaded forward end 36 of the shaft. The rear end of the operating shaft is also threaded and projects beyond the bearing 33 for re ceiving a retaining nut 37.

Beyond the bearing 31 a beveled gear wheel 38 is secured to the operating shaft by means of a pin 39. A spur gear 40 is provided with a hub 41 which embraces the shaft and extends through the inner ring of the ball bearing 33. This spur gear is mounted on a polygonal section 42 of the shaft. A cam disc 43 has a bushing 44 pressed in a central aperture therein and this bushing is rotatably mounted on the shaft 30 between the bevelled gear 38 and the spur gear 40. i The rear plate or web 32 has inserted therein a number of pivot pins 45 on which are rotatably mounted pinions 46 which are adapted to mesh with the spur gear 40 and the teeth of an internalgear 47 carried by the cam disc 43.. According to this arrangement, therefore, rotation of the shaft 30 in one direction results in rotation of the cam disc in the opposite direction.

The cam disc has secured thereto a suitable cam 48 by means of rivets 49, this cam having the on and off positions indicated at 50 and 51, and cam surfaces connecting these extreme posit-ions. A cam guide 52 is also riveted to the cam disc and is arranged in spaced relation to the cam to provide a cam groove 53 adapted to act as a track for a roller 54 carried by a compensating lever 55 which is rotatably supported upon a pivot pin 56. A throttle lever 57 is also rotatably mounted upon this pivot pin and the two levers are held in adjacent position by means of the nut 58 engaging the exposed threaded end of the pin. The compensating lever 55 carries the cam roller 54 which is spring pressed by means of a leaf spring 59 secured at one end to the compensating lever and bearing at the other end against the roller. This spring tends to urge T e compensating lever is provided with a lug 60 which is adaptedto engage the throttle lever and move the same with the compensating lever for the purpose of moving the throttle valve toward closed position. The compensating lever is also provided with upstanding lug 61 and the throttle lever is provided with the lug 62, which lugs are connected by means of a coil spring 63. This coil spring allows the throttle valve to be manually moved to off position irrespective of the position of the cam roller and also acts to move the throttle valve toward open position in accordance with the posit-ion of the cam roller on the cam.

The stub shaft 27 is provided at its rear end with bevel pinion 65 which is suitably keyed to the shaft and meshes with the bevel gear 38. The stub shaft 28 is in like manner asleeve 84.

provided with a bevel pinion 66 which meshes with bevel gear 38. The forward projecting end of the stub shaft 27is adapted propeller reversing mechanism 11 by suitable means including a shaft 67 and suitable couplings 68 and 69 between the forward and rear ends of shaft 67 and the corresponding ends of the shafts 12 and 27 respectively.

The auxiliary control means 20 consists of a bracket 70 adapted to be secured to the fuselage of the aircraft at the rear cockpit. Anoperating shaft 71 is rotatably mounted in a central boss 72 of the bracket. This shaft has secured thereto at one end the operating hand wheel 73 and at the other end a bevel gear" wheel 74 is keyed. The bracket 70 is also provided with end bosses 75, 76 and in the latter a stub shaft 77 is rotatably mounted. A pinion 78 is keyed to this stub shaftand meshes with the gear wheel 74. A shaft 79 extending through the boss is connected to the stub shaft 77 by a suitable flexible coupling 80 whereby rotation of the auxiliary operating shaft 71 and bevel gear wheel 74 drives the pinion 78 and the shaft 79. An idler pinion 81 is rotatably mounted on the shaft 79 near the boss 75 and meshing with the bevel gear wheel 74 acts as a guide for the same Nuts 82 engaging threaded portions-of the shaft 79 serve to retain the bevel pinions 78 and 81 in correct position. The forward end of the shaft 79 projects beyond the boss 75 and is provided with a key 83 adapted to engage A similar sleeve 84 is keyed to the shaft 28 of the forward control bracket and a shaft 85 is connected to said sleeves at opposite ends by universal couplings 86 and 86.

The main control bracket has pivotally mounted thereon the spark lever 87 and the mixture control lever 88 in addition to the throttle lever 57. This spark lever is connected to the ignition devices 18 of the engine by the links andv levers 19 previously mentioned and is'also connected to the auxiliary spark lever 87 pivotally mounted on the rear control bracket 70 by means of link connections 89. The mixture control lever 88 is connected to the adjusting device 8 by the rods 9 and is also connected to theauxiliary altitude mixture control lever 88' pivotally mounted on the rear control bracket 70, by means of link connections 90. The auxiliary throttle lever 57 is connected to the throttle lever 57 by rods 91 which are pivotally connected at-opposite ends in apertures formed in the lower ends of the main and auxiliary throttle levers respectively. The main throttle lever 57 is also connected to the throttle valves 16 by means of the links and levers 17 According to the construction described above movements of any to be connected to the shaft 12 of the.

of the forward or rear control levers 57, 57

87, 87' or 88, 88' will impart corresponding movements to the throttle valve, ignition control device, or mixture adjusting device respectively.

Rotation of either of the operating hand wheels 34 or 73 will change theangularity of the propeller blades and at the same time the cam 48 acting upon the roller 54 of the compensating lever actuates the throttle levers to automatically control the throttle valves of the engine in accordance with the existing angularity of the propeller blades. When the roller 54 is engaged in cam track 53, and the cam disc 43 is rotated in the direction of the arrow shown in Figure 6 the lug 60 of the compensating lever contacting with the throttle lever gradually moves the latter toward closed position. Simultaneously the reversing mechanism 11 is changing the angularity of the propeller blades toward zero thrust position. Continued r0- tation of either of the operating wheels 34 or 73 will gradually open the throttle valve and increase the pitch of the propeller blades in a reverse direction for slowing down the speed if the aircraft until the part 50 of the cam is again in contact with the roller.

When the airplane iscoming to a complete stop under the influence of the reversed propeller blades, as in landing, and it is desired to reduce the thrust of the propeller quickly, the throttle levers 57, 57 may be moved manually toward closed position in which case the throttle lever 57 takes a position indicated by the off osition in Figure 6. To restore the roller into the cam track it is only necessary toreverse the direction of the cam disc when the laterally inclined surface 94 and upwardly inclined surface 95 of an auxiliary cam plate 96 earned by the cam disc will direct the roller against the cam 48. The s ring 59 permits the roller to yield upward y under the influence of surface 95. If the disc be rotated in the direction of the arrow of Figure 6 instead'of in the reverse direction, the roller will be guided into the camtrack 53 by a projecting cam surface 97 on the cam plate 96. It will be noted that the portion of the cam surface corresponding to the on position of the throttle valve is substantially circular so that the throttle the blades thereof, multiple control means for simultaneously actuating said mechanism and the throttle valve of the engine in predetermined relation, and compensating devices for permitting the manual actuation of said throttle valve toward off position independently of said means.

2. In an aircraft having an internal combustion engine provided with a throttle valve, the combination with a propeller, of mechanism for changing the angularity of the blades thereof, a main control bracket, means mounted on said bracket for simultaneously controlling saidmechanism and the throttle valve of the engine in predetermined relation, transmitting devices connecting said reversing mechanism and said means, and auxiliary control mechanism connected to said means.

3. In an aircraft having an internal combustion engine provided with a throttle valve, the combination with a propeller, of mechanism for changing the angularity of the blades thereof, a .main control bracket, :1 control shaft rotatably mounted in said bracket, a cam disc mounted on said shaft, a throttle lever adapted to be actuated by said cam disc, gearing connecting said shaft and disc, an auxiliary control means, transmitting devices connecting said means and shaft, and means connecting said shaft and mechanism.

In testimony. whereof I have aflixed my signature.

ERNEST G. MoCAULEY. 

